PLANT EXPRESSED CELLULASES FOR THE PRODUCTION OF BIOFUELS

SYNGENTA has pioneered the concept of plant expressed enzymes for biofuel production, and is continuing to develop crops tailored for next generation biofuel production by expressing optimised enzymes in planta for the conversion of cellulose to fermentable sugars. Agricultural waste streams such as corn stover, corn cobs and sugarcane bagasse are attractive potential feed stocks for advanced second generation biofuels due to their comparatively low cost, abundance and availability. A sugarcane mill processing 7 million t/y will generate close to 2 million t/y of wet bagasse. Given that about one quarter of this material is cellulose, then more than 12 000 t/y of enzymes are needed at current enzyme loadings to convert the cellulose to fermentable sugar. Producing this much enzyme by microbial fermentation requires twelve 100 000 L/d fermentors operating at 100 g enzyme/L ferment for a year. In an alternative approach, Syngenta has demonstrated the production of several classes of cellulases in maize and shown that they are nearly as active as their microbially produced counterparts. Furthermore, maize- expressed cellulases were tested on pre-treated sugarcane bagasse. To make sugarcane production and delivery of cellulases a reality, Syngenta recently formed the Syngenta Center for Sugarcane Biofuel Development (SCSBD) in collaboration with the Queensland University of Technology, Brisbane, Australia to develop efficient sugarcane transformation technologies. By providing technologies like these, Syngenta is helping to make second generation biofuels economically viable, while reducing agricultural waste and increasing the value realised from a hectare of land.